package com.uinfor.lb.impl;

import com.uinfor.lb.LoadBalance;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.stereotype.Component;

import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * @descripttion:
 * @Author: WZH
 * @Date :2021/1/22  9:17
 **/
@Component
public class MyLb implements LoadBalance {
    private AtomicInteger atomicInteger=new AtomicInteger(0);
    public final int getAndIncrment(){
        int current;
        int next;
        do {
            current=this.atomicInteger.get();
            next=current>=2147483647 ?0:current+1;
        }while (!this.atomicInteger.compareAndSet(current,next));
        System.out.println("**********第几次访问next"+next);
        return next;
    }
    @Override
    public ServiceInstance instance(List<ServiceInstance> serviceInstances) {
        if (serviceInstances.size()!=0) {
            int index = getAndIncrment() % serviceInstances.size();
            return serviceInstances.get(index);
        }else {
            return null;
        }
    }
}
